This two-horned rhino is the smallest and most threatened of the five living rhinoceros species. It is sometimes referred to as the ‘hairy rhino’ because of the long coarse hair that covers its body. The species leads a solitary life deep in the rainforests of South East Asia, where it has survived virtually unchanged for a million years. Sadly, human activities have brought the species to brink of extinction. Extensive deforestation and poaching for the horn have caused a dramatic decline in rhino numbers, and it is estimated that fewer than 275 individuals survive today in very small and highly fragmented populations.

The Sumatran rhino, EDGE mammal number 10 is the most endangered of all rhinoceros species because of its rapid rate of decline. This extraordinary speci...
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Evolutionary Distinctiveness

Order: Perissodactyla

Family: Rhinocerotidae

Together with equids (horses, zebras and asses) and tapirs, rhinos are the only surviving members of an ancient and formerly diverse group of ungulates, which originated in the Eocene around 50 million years ago. The Sumatran rhino is the only surviving member of the most primitive group of rhinos, the Dicerorhinini, which emerged during the Miocene, 15-20 million years ago. It is closely related to the extinct woolly rhinoceros (Coelodonta antiquitatis), which lived in Europe and Asia until 10,000 years ago. Ancestral members of this clade are thought to have migrated into Africa and evolved into the two species now found in this continent, the black rhino and the white rhino. The Sumatran rhino is therefore thought to be more closely related to these species than to either of the one-horned Asian species.

Description

Size:

Head and body length: 236-318 cmShoulder height: 112-145 cm

Weight: 600 - 950 kg

Often referred to as the ‘hairy rhino’, the Sumatran rhino is the smallest of the five living rhinoceros species. It has a sparse covering of long coarse hair on its body and tufts of hair on its ears. The skin is reddish-brown and deeply folded behind the front legs and in front of the hind legs. It is the only Asian rhino to have two horns, although the posterior horn is usually very small and often absent in females.

Ecology

The species is a browser, feeding on a wide variety of plant material, including fruit, leaves, bark, shrubs and vines. Most of the 50 kg of food the rhino consumes each day comes from saplings, which it breaks down in order to reach young leaves and shoots. The rhino is particularly fond of wild mangos, bamboo and figs, and obtains essential minerals from salt-licks. Individuals prefer to travel and feed at dawn or dusk or during the night, when it is cooler. Days are usually spent resting and wallowing in mud to keep the skin cool and insects at bay. The rhinos are solitary creatures and tend avoid each other, coming together only for breeding. Females maintain stable, partially overlapping home ranges, while males are slightly more nomadic. The large ranges of males overlap extensively, but there appear to be small, exclusive core areas. Both sexes mark their territories with faeces, urine and soil scrapes. In some areas the rhinos have been seen to exhibit seasonal movements, moving to higher ground during the wet season to escape flooding and descending again once the rains have finished. The lifespan of the Sumatran rhino is thought to be similar to that of other rhinos, at around 35-40 years. Sexual maturity is reached at 6-8 years of age and females give birth to a single calf every 3 to 4 years.

Habitat

Mainly found in hilly country near water. It inhabits both tropical rainforest and mountain moss forest. The species is thought to prefer lowland secondary forest, where the canopy is broken and the smaller shrubs and vines on which it feeds are more abundant. Individuals can, however, be found in a wide variety of habitats. An agile climber, it is sometimes forced up into higher altitudes due to lowland flooding or human pressures. The rhino is quite capable of surviving in such areas providing there is sufficiently thick undergrowth and a salt-lick (essential for every home range).

Distribution

Once found throughout south-east Asia, the species now exists only as small, highly fragmented populations scattered throughout its former range. The largest concentration of the western subspecies is thought to be in Sumatra and Peninsular Malaysia (with possibly a few surviving in Thailand along the border with Malaysia). There have also been unconfirmed reports of the rhinos in Cambodia, Laos and Vietnam. The eastern subspecies is currently found only in Sabah in Malaysian Borneo, although there is also speculation that it may exist in the neighbouring state of Sarawak and in Kalimantan (Indonesian Borneo). The subspecies D. s. lasiotis is probably extinct, although a few individuals may possibly survive in the forests of Burma.

The population size is critically low. There are thought to be as few as 275 Sumatran rhinos surviving in the wild.

Population Trend

Numbers have halved over the last decade, although this decline appears to have been slowed and numbers seem to be stabilising in most of the core areas.

Status

Both the Eastern and Western Sumatran rhino are classified as Critically Endangered A2abd; C1+2a(i) on the 2010 IUCN Red List of Threatened Species, and D. s. lasiotis is classified as Extinct. The species is listed on Appendix I of CITES.

Threats

Hunting has been a major factor in the decline of the species. Rhino horn, along with various other body parts, has been used in traditional Asian medicine for centuries to treat a variety of ailments, including fevers and strokes. Although hunting is now illegal, poaching continues, with animals continuing to be trapped and killed for their horns. Loss of habitat as a result of logging and conversion of land to other uses is the other main threat. As areas of suitable habitat become fewer, the rhino populations are pushed together into small, fragmented subpopulations that may be too small to be viable. Stranded in these remaining pockets of forest, the rhinos become even more susceptible to disease, environmental disasters and poaching.

Conservation Underway

Surviving rhino populations are being intensively protected by anti-poaching patrol teams, which have proved very effective at reducing illegal poaching. The teams are also involved in monitoring rhino populations, with the information gathered being used by the Indonesian and Malaysian governments to develop effective management programmes. Some of these programmes have involved creating breeding sanctuaries where the rhinos can be protected and maintained under conditions most suitable for reproductive success. The governments are assisted in their work by several national and international conservation organisations which are also restoring habitat in heavily encroached areas.

The IUCN/SSC Asian Rhino Specialist Group (AsRSG), the co-ordinating body for rhino conservation work, has developed an Action Plan for conservating this species. This plan recognises the importance of involving local communities in their work, so that they can learn about the rhino's plight and benefit from its conservation. Such communities are also being encouraged to adopt sustainable methods by which they can effectively manage natural resources without causing further harm to the rhino or its habitat. In addition to these measures, conservation groups are trying to reduce the demand for rhino horn by conducting awareness campaigns in consumer countries, and investigating possible alternatives to rhino horn in traditional medicine. At present, all trade in rhino horn is prohibited, and the extent of illegal trade is investigated by TRAFFIC (the wildlife trade monitoring network of the WWF and IUCN).

The Borneo Rhino Alliance (BORA) is currently implementing two courses of action to stop the Sumatran rhino from drifting to extinction, and to initiate a trajectory of increasing rhino numbers: the first is to have zero poaching and trapping of rhinos anywhere in Sabah, and the second action consists of a “Rhino Rescue Programme” and establishment of a “Borneo Rhino Sanctuary” in Tabin Wildlife Reserve. The Borneo Rhino Sanctuary will be developed as a large fenced area inside Tabin Wildlife Reserve, to be populated by rhinos translocated from sites where they are not breeding. The small population of rhinos in Tabin and Borneo Rhino Sanctuary will be managed in an attempt to boost the breeding rate, as well as to prevent the death of rhinos by illegal hunting and trapping.

Conservation Proposed

All of the above initiatives need to be reinforced and expanded. Existing rhino populations are in need of more protection, and additional habitat should be made available once numbers start increasing. In particular, habitat corridors should be created to allow individuals passage between currently isolated populations. Captive breeding has proved notoriously difficult for this species, but the recent births of Sumatran rhinos at the Sumatran Rhino Sanctuary (SRS) in Sumatra and Cincinnati Zoo has created a fresh impetus for this approach. Many groups argue that captive management of the species in sanctuaries is the best way forward.

In addition to work on protecting the rhino and eliminating illegal trade in rhino horn, surveys of rhino habitat should be carried out immediately in areas of where there have been unconfirmed sightings (such as Kalimantan). The rhino population is so critically low that any currently unprotected populations require immediate attention. Only a few fertile breeding adults are left, and is it becoming more unlikely that these animals will ever come into contact with mates with which to reproduce. Monitoring and intervention is needed to prevent inbreeding of existing populations, which has the potential to make them more vulnerable to factors such as disease or deleterious mutations.

International Rhino FoundationThe IRF was founded in 1993 in response to the global crisis in rhino conservation. The IRF is a collaborative conservation initiative providing technical, administrative and financial services and support for scientific research and intensive management for both captive and wild rhinos. IRF has from its inception concentrated its Asian Programs on the Sumatran rhino, probably the most endangered of all rhino species and is actively involved in maintaining the International Studbook for the Sumatran rhino.

Save the Rhino InternationalSave the Rhino International works to conserve genetically viable populations of critically endangered rhinoceros species in the wild. Our aim is to increase rhino numbers by providing financial and in-kind support for rhino projects and for community-based initiatives.

WWFThe rhino is one of WWF flagship species, acting as an ambassador and highlighting the need for conserving the habitats in which they live. WWF works across the globe and aims to tackle the main threats facing rhino by strengthening protected areas in Asia, lobbying to halt the illegal timber trade, and stamping out the illegal trade in horn.

Rhino Resource CentreThe Rhino Resource Center is committed to assisting research and conservation of the rhinoceros worldwide by collecting all publications and maintaining archives. The website provides data on all published work on each of the five species of rhinoceros.

BORA is a local NGO based in Sabah. Active since the year 2000, and formerly known as SOS Rhino and subsequently SOS Rhino Borneo, BORA provides protection and monitoring of a critical population of Sumatran Rhinos in Tabin Wildlife Reserve in eastern Sabah.